hi everyone I'm trying to tune my 09 ctsv but I'm running into an issue when dialing in the air frequency table. I will list the hardware I'm using for tuning along with the settings I'm editing in order to force the ecu into maf below the explanation of my issue.
the issue I'm having is that whenever I start the car it runs way over rich (6.7-7.4 lambda) so ill go out and drive and populate the histogram till I feel I have a good average in all the cells I can hit. then ill take the data from the histogram and copy that to my air frequency table using multiply percent half. the percentage in the cells is usually -20 when this happens so figure I'm pulling 10 percent fuel out. now here's where my issue develops ill load in the new file but the car will still idle at 6.7-7.4 lambda. if I go and drive it 2-3 miles and come to a stop it will then idle at 1.10 lambda (the limit of my WB setup) and the car is noticeably running rough. its as if there's a table I'm not disabling that's adding fuel on startup but goes away after a short drive.
the next issue I'm running into effects the rest of the air frequency table. starting out the car was running rich well say for example -10 to -15 percent for the 6150hz to 7050hz range in the histogram so ill take that and modify the air frequency table using multiply by percent half. then when I go to drive the car to gather more data there will be a dead lean spot in that same HZ range that causes the car to stumble and the histogram will report a 6-7 percent error which would be about the same amount of fuel I just removed. the only thing I can figure is that I'm getting bad data on decell. I had a similar issue when I was tuning the vve but I was able to get around it since the decell data only really effected the area below 35 KPA.
thanks in advance for any advice ill also include my tune file and my vcm scanner setup if i can.cts v2 headers afm tune 9.hpt
setting changed for maf tuning:
dynamic airflow high rpm disable set to 100 RPM
dynamic airflow high rpm Re-enable set to 8000 RPM
long term fuel trims min ect set to 400
long term fuel trims max ect set to 10
O2 reediness ect set to 400
COT set to disable
DFCO enable ect set to 400
DFCO dissable ect set to 399
car details:
09 CTS V
E67 ecm
long tube headers with 3 inch exhaust
flex fuel sensor
FIC 1000cc injectors
rotofab Cai
tuning hardware:
Ballenger AFR500c (data is brought into vcm scanner over can bus and O2 sensor is mounted about 8 inches from header collector)
mpvi2 interface